This invention relates to a method and an apparatus useful to form the electrical lead wires of an integrated circuit package. Leads are usually wires rectangular in cross-section, which electrically connect an integrated circuit, encapsulated in a plastic or ceramic material, to a printed circuit board (PCB). The leads also physically attach the integrated circuit package to the PCB.
Economy of space is of critical importance when designing printed circuit boards for use in modern electronic apparatus, such as computers. Large quantities of dynamic random access memory (DRAM) devices are required by current computers, most of which are mounted on PCBs. To increase the density of DRAM devices on a PCB, zig-zag in-line packaging (ZIP) DRAM devices can be used, effectively doubling the memory density on a PCB, compared to conventional dual in-line packaged (DIP) DRAM devices.
ZIP device leads are formed with two bends. For instance, a 16 lead ZIP is manufactured with 16 co-planar leads emerging from one side of the device package. The first bend forms the leads at an acute angle to the original plane of the leads, while the second bend returns the distal portion of the lead to a plane parallel to the original plane of the leads. Heretofore, this double bend has been applied to the leads in a single operation by bending the leads with a punch against an anvil.